1. Field of the Invention
The present invention relates to metal nanowires from which a transparent low-resistance conductive layer can be formed without the aid of antioxidants, a method for producing the metal nanowires, and an aqueous dispersion thereof.
2. Description of the Related Art
As a method for producing an aqueous dispersion of metal nanowires with a long-axis length of 1 μm or more and a short-axis length of 100 nm or less, a method is proposed in which a polyol dispersion of silver nanowire is prepared by a polyol process, and a solvent contained in the polyol dispersion is substituted with water through centrifugation to thereby produce an aqueous dispersion of metal nanowires (see U.S. Published Patent Application No.2005/0056118 and U.S. Published Patent Application No. 2007/0074316).
Furthermore, U.S. Published Patent Application No. 2007/0074316 and Japanese Patent Application Laid-Open (JP-A) No. 2004-196923 propose a transparent conductor made of metal nanowires. In practical use of metal nanowires, the resistance is disadvantageously increased because of oxidation of Ag. In order to prevent the increase of the resistance, an antioxidant is added to metal nanowires or an overcoat layer is applied on metal nanowires. However, since the antioxidants or the overcoat layers used in the above-mentioned metal nanowires are not conductive and their effects do not last permanently because their materials are organic substances, further improvements of metal nanowires are desired at present.